Illusory staircase



July 4, 1950 J, c 2,513,914

ILLUSORY STAIRCASE Filed April 2, 1949 2 Sheets-Sheet 1 7 INVENTORJOHNP. CAHM 49 4a ATTORNEYS.

- July 4, 1950 CAHN 2,513,914

ILLUSORY STAIRCASE Filed April 2, 1949 2 Sheegts-Sheet 2 IN VEN TOR JOHNP. CAHN.

A T TORNEYS.

Patented July 4, 1950 UNITED STATES PATENT OFFICE 2,513,914 ILLUsoRYSTAIRCASE John P. Cahn, San Francisco, Calif.

Application April 2, 1949, Serial No. 85,110 12 Claims. (01. 272-8) Thisinvention relates to display apparatus and particularly is directed to aform of device usable for creating optical illusions especially desirabfor advertising purposes.

In its essence the invention is directed to a de-, vice wherein recoursemay be taken to units adapted to portray unusual and novel effects ofsuch a nature that observers are tricked tobelieve elements actually notphysically present are being worked with inthe obtainment of fancifulresults. i

The invention herein to be described embodies an advertising device fordisplaying various ob-' jects or persons in unusual and abnormalpositions relative thereto. In one form of the unit there is provided arising section in the form of a staircase which is completely usable inits initial state in all respects. The staircases has positionedadjacent thereto a banister and a hand support railing which rises fromthe end of each step of the complete staircase. Between .the staircaseproper and the railing is a panel section to enclose the completestaircase and to provide the appearance of a solid section between therailing and the various steps comprisingthe staircase. I I The staircaseas it is constituted for utilization as an advertising medium is formedbroadly into three separate sections of which the lowermost section andthe uppermost section each comprise a plurality of steps fixedlysupported relative to the hand railing and the paneling. 'A movablesection comprising generally two or three steps of the completestaircase is positioned at an intermediate location between thetop andthe bottom of the staircase section as a whole. This movable stepsection is arranged and positioned so that in its unused state itnormally so fastens or locks in place withrespect to the fixed stepsection as to provide a staircase upon which those using the device fordisplay or, ad-.- vertising purposes may readily walk up and down, andwhich mayreadily be examined by ,the.lok'-{ ing audience to create theillusion whichis to be formed. Fastening elements, usually'positioned atthe top and bottom of each handrail, as well as an intermediate point.thereof which coincides with the position from which themovable' stepsection is to be withdrawn from the main fixed top and bottom stepsection, are provided so that various arrangements of ropes, chains,wires, tapes or the like may be strung between these various fasteningor connecting points. Such strung tapes or ropes or the like serve thepurpose generally of preventing thelooking audience o ov up and down thesteps during the time the illusionsare produced and also serve formasking the motion of any movable parts relative to other parts of thedevice.

For display, illusory, advertising and generally related purposes themovable step section is ar-, ranged to slide inwardly or laterally withrespect to the fixedv step section. At the timesthat this lateral motionof the movable section is initiated a reflecting member is positioned tomove imme diately in front of th space formerly occupied by the movablestep section and closelytadjacent the fixed section so as to be raisedrelative-to the. lowermost fixed step section so that the viewingaudience-looking at the complete step section will see in the reflectorthe lowermost fixedstep sec tion which will then appear as if it werethe now removed movable step section. The retraction of the movable stepsection and the elevationof the reflecting member provides in thecomplete staircasean opening intermediate the uppermost fixedstepsection and the rear surface of the re-, flector through which objectsor persons may be moved relative to the reflecting bodysoas topro jectbeyond the outer edge thereof and thenjtoassume,as far as the lookingaudience is concerned, a position by which they appear to floatf orrprotrude abovethe step section as a whole, and thus actually give theappearance of having moved outwardly and through a staircase section. By

stringing ropes, tapes or the like between the fas-' tening members itwill be appreciated that the shadows and masking effects therebyintroduced. serve to hide or obscure the edge as well as any motion ofthe reflecting member insofar vas ,the looking audience is concerned.

In its general operation the movement of the movable step sectioninitially is only that amount which is required to permit the reflectingbody to be moved betweenit and the lower fixed step section so thatminimum opportunity ofthe look-' ing audiencetosense the removalinitiallyi of a portionof the complete staircase exists. After thereflecting member has been moved outwardly to its extended position toreflect the lower fixed step section it is, of course, immaterial asto'the. extent of motion which is later given to the mow able stepsection.

Generally the complete staircase section is mounted or supported 'on adisplay platform; The sides of the staircase are enclosed sov that ahousing arrangement is formed by the staircase itself and by theenclosed sides. The movable step section isarranged to slidev into theso}; formed housing. If it. be desired thatthehea d of a human being becaused to appear to extend outwardly and to be suspended above or toprotrude from the staircase section itself the person or persons so tobe exhibited are normally moved within the housing prior to thecommencement of the exhibition. With the movement of the reflectingmember outwardly and the movement of the movable step section inwardlyinto the housing an enlargedlopeningis formed intermediatethereflectorfand the upper fixed a step section so that the person can thenmove within the housing to a position such that the head, for--instance, extends above the top of the reflecting member and appear tolookers as extendingdirectly outwardly from or floating,above-the-.

steps as a whole.

With these features in mind it becomes the whichtserves"to-mistify andintrigue-'the-looking audience; a

th 1"objects-"andadvantages of-"th'e inven-' tionwill' become apparentand at "once suggest themselves to' those'skilledin the art to which"the-invention isdirected upon readingthexfol lowing descriptionand-claims in connection with the accompanying drawings wherein: 1

Fig. 1 isa. schematicview to represent the staircase and, theexhibition: platform" used thereby in its-initial state prior toutilization for exhibition purposes;

Fig,..2 is a sectional viewlooking; at aportion' of 'tlie'staircasesection of Fig, 1":from e-16w and-shows the fixed, and movablestep-sections in positionsuch' asto form-1a-normally 'solid staircase;

Fig; 3...is 'aivi'e'w of "the same; general type'as Fig. 2ishowing themovable step section-removed from f the fixed, step sections-and theillusion: creating; reflector likewise moved to" portray thepresence'ofthe .fixed step section in amanner togsimulate the movable;section; a V c Fig/Ans an enlargedsection eta-portion" of Fig;- 2 Ttoindicate. particularly. the stair locking and moving mechanism;

Fig. 5 is a front .view of a portionfof the-step; section .of Fig.1.,with ropes or tapes positione'dwith'respectto' the;railingand'fpaneling so that the movable. step; section" may 'be 'slidably re:movediiro'm, the fixed "step section with a a mini?mum-opportunityfordiscernment; a I

Fig; 6 ;is. a sectional .view of aj portion. of "the panlingbiFisl;5""to illustiiate" particularly the locationioik'the.rope-or tape,fastening means witlrre'spectfto 'the-.paneling.; i Y 1 I Fig; 7;. is;an enlarged view "of"' a portion" of Fifg fi ,to. .show, 'in.furtherdetail the rope or'tape fastening mechanism; and," I

Fig,=.8 is a..detail.of therope fastening -mecha; nismioffl ig,.-7.takenonthe l'me ,8-8 of Fig. '7 lookingjnthe; direction of the arrows.

.R'efrrifiglnow. tothe; drawings, ,for a further understanding ofjtheinvention, and first to. Fig. 1,I it' will belseenjthata staircasesection'l I com-, prising a multiplicity of stepsimayube "supported forexhibition purposes upon'a platform l3. At

4 the lowermost end of the staircase H is a balustrade or banister [5which is topped by a handrail l1 between which and the staircase properare sections or paneling l9 each having grooved members 2| extendingoutwardly from the junction of the tread and riser section of each stepof the staircase and the handrail. The direction of the grooves or slotsis at an angle of substantially45 to the horizontal tread sectionof eachstep and the vertical riser-section of each step, or, in other words, ina direction coinciding with that of the bisector of the angle formedbetween the tread and riser section of each of the several steps; Theouter section of the paneling I9 is likewise provided with similargrooves or slots 23, although, as will be apparent from an obser-VEL'l'iiOIIKOfTFig. 8,- it is not essential or necessary that suchgrooves or slots originate at any particular locus relative to. the stepsection. Side support members 25 and vertical upright supports" ZT'Whichserve-to brace-the complete step section'are' also provided as apart ofthe-installation. I

Additional paneling members 29,- likewise grooved, fill'thespacebetween-the side support 25*andthevertical supports '27 so'as 'to form a-housing and enclosure forthe complete section withone-outer surface ofsuch housing being formed by the step section itself;

Ascan be noted particularly from Fig. 5'; a tape or rope maybe drawnbetween the upper-' mostend of the railing l1 and across the steps.Likewise, at the bottom of the railing [1 an additional rope-or tape 3|may be strung. At a point intermediate---the-topand bottom of each ofthe handrail sections IT and withinthe groove" or slot '31 extendingoutwardly to the handrail'from the intersection of the riserelement ofthemovablestep section and the tread "section 35 of the lowermost fixedstep section 36 there is'a further fastening hook or the like 38,whichis shown'particularlyrin Figs. 6, '7 and 8. The-hook 38 is''carried in the-grooveor slot-32and secured therein by-means-of theouter paneling section surfaces [9 with respect to the inner panelingsections 39 (see Fig. 8).

Attimes whenthe optical illusion is to be created, a demonstrator maysecure a rope or tape which is to be strung over and above the stepsection first, for instance, atone of the lower fastening elements-onthe rail 11 and such rope then; for instance, may, bestrung to followthe paths indicated byjthe arrows on Fig. 5 was to wrap aroundthe'uppermostropeor tape 30 then downwardly tothe lowermost fasteningsection omth'e opposite rail I'I'and'then' to'the'hook orfastener38fintermediate'the length of the railing' 1 1 and thence acrossto the corresponding hook 38' beneath-the opposite railing. section l'ifrom which it passesto' the hook 'at'thelowermost'l section'oitherighthandrailing IT. Thus the horizontal or substantially horizontal tapeor.ro'pe isnow'positioned at the uppermost edge of thegrooveQor slotwhichis above the junction. Thus, the tape or rope'40 between thefasteners 38. is now positioned substantially parallel to the junctionof .the riser "and tread sections 34 and..35i of the? movable and fixedstep sections 33and 36.v v I I At times when the movable step'section'is to be retracted to create the desiredoptical illusion provision mustbe 'made for unlocking this step secti'onifrom its..pos ition relativeto the fixed step. section .to'; form a usable staircase.- The movable"step section 33 is supported in the modisupport groove 32.

fication shown upon'a pairo'f' guide'rails '40 and 4|, supported at eachend of the step section and while not shown may be carried or supportedfrom the more rigid support member '25. In one form of the hereinprovided arrangement the movable step section 33 is arranged to slide onthe guides 40 and 4| by roller contact with bearing elements 43. Theseelements are generally brass or other suitable metal having therein agroove extending circumferentially and into which groove rubber or otherflexible material may be fitted to provide and insure substantiallysoundless lateral motion of the step section upon the guides. A stop 44or the equivalent is usually arranged to limit the motion of the stepsection inwardly.

Locking of the movable step section in a position to make the staircaseusable isprovided by means of the arm 45 carrying a fastening detentelement 46 which is arranged to hold against a recess 41 on the rear ofthe riser-of the movable step section, for instance. Release of themovable step section for lateral movement within the housing is providedby any suitable means mechanical or manual to exert a slight pressure orpull upon the arm 45 to cause the arm to rotate slightly in a clockwisedirection to cause the locking pin or detent 46 to move out of therecess 4! to the position indicated by dotted outline in Fig. 4immediatelyto the left of the fixedly positioned step section. Suchmovement will permit the pin or detent 46 to rest into a second recessor slot 48 to hold the movable step section in a semi-permanently lockedstate relative to the fixed step section. Lateral movement of the stepsection 34, however, provides an opening between the fixed step section35 and the movable step section 34 through which a reflector element 49may be passed. The reflector 49 is of a length slightly in excess of thelength of the steps by an amount necessary to permit it to fit withinthe grooved member 32 of the various grooves or slots 2| formed in thepaneling l9 between the railing sections l1 and the steps I l All ofFigs. 2, 3, 4 and 7 particularly represent the positioning of thereflecting member 49 relative to the steps II and to the mirror In Fig.2 the reflector 49 is in its retracted position and resting upon itssupport 5|, whereas in Fig. 3 the mirror or reflector 49 is shown in anextended position. To extend the reflector 49 outwardly from theposition shown by Fig. 2 to that shown by Fig. 3 it can be seen that thecounter-weight 50 will at the time the movable step section is drawnlaterally into the housing serve to balance substantially the weight ofthe reflector so that slight pressure exerted against the reflectorbydownward pull on the counter-weight or an upward push on the reflectorwill cause the reflector to move in the space between the steps andalong the grooved path 32 to that position which is indicated, forexample, by each of Figs. 3 and 7.

The release of the movable'step section from its locked positionrelative to the fixed step section where it forms the usable staircaseis provided generally by means of a person conventionally represented at52 located within the housing. Likewise, the same person usually movesthe counter-weight 50 downwardly to bring the mirror or reflector 49into its proper position for reflecting the lower fixed step section. Atthe time periods when the reflector 49 is moved to that position'shown'in'Fig'. 3, for

instance, the arm 45 is again moved downwardly from its position suchthat the detent and pin 46 arein semi-permanent locking position. Thisthen will permit the movable step section to slide to the left from itsposition shownin Fig. 2 to that position shown in Fig. 3 with thecounter weight 55 serving generally to balance the Weight of the stepsection so that the person 52 within the cabinet will have no difficultymoving the steps 34 laterally. The position of the movable step section34 to form a usable staircase, and later to permit outward motion of themirror or reflector 49 to provide the maximum lateral shift relative tothe housing and such as to bring the step section up against'the stop 44is represented particularly by the showing of Fig. 4 which is anenlarged section of that which is shown by each of Figs. 2and 3particularly.

It can be seen that with the movable step section retracted and drawninto the cabinet or housing, a reasonable amount of space exists to theleft of the reflector 49 as it is shown in Fig. 3. This space isadequate to permit the person 52 located within the housing formed tothe rear of the steps to assume a standing position, as in Fig. 3, incontrast to the crowded and sitting position in Fig. 2. At the same timethe person housed within the cabinet is able to move through the openingnow provided between the two fixed step sections (or where only a lowerfixed step section exists, to the rear of the mirror) to a position suchthat the head 51, for instance, extends upand above the top of themirror. To a looking audience viewing the staircase section fromsubstantially the front, that person will then appear in the stepsgenerally above the tape or rope extending transversely between thehooks 38 as suspended above the step section and located in one of theareas identified particularly between the various strung ropes or tapes.

The position of the mirror, in the position shown by Fig. 3, forinstance, creates the illusion of the actual presence to'the left of themirror of the movable stepsection which has actually been removed.Because the looking audience sees in the mirror or reflector 49 from thefront the image of the lower fixed step section appears in such a waythat the tread sections of the fixed steps appear in the mirror as ifthey constituted the riser sections of the movable step section. It isusually preferable to have the mirror or reflector 49 of the frontsurface reflection type to improve the illusion, although this is not anessential factor of the invention and the normal rear surface reflectingmirror is also usable.

" In staging a demonstration of the character necessary for theutilization: of this invention as an advertising medium the person 52positioned within the housing and who moves to such location that hishead'51 protrudes beyond the edge ofthe mirror to appear as if suspendedabove the steps frequently may wish to create a further form of opticalillusion and to appear as if rising still further above the steps. Tothis end the hooks 38 which fasten the tapes or ropes 40 are generallycarried on a slider block 6| positioned in a recessed portion 62 of themain panel 63 located immediately behind the paneling surfaces l9 whichprovide the slots or grooves 2 I. The extent of this recess is to a veryminor distance below the bottom edge of the handrailing I! so that tothe unsuspecting looking audience the r opes or tapes 40, when they arefastened, ap-

pear: generally to extend-"outwardly from the :bot-

tom ofxthe:railing-ll. It will: be-observed that withthemir'ror orreflector 49 in its extended po. sition itmoves toaposition.substantially-adjacent the rope section which extends parallelto'the junction of itheiriser: and-tread sections of .the'

steps; Thus it becomes-necessary if the-head?! of'ftheexhibitor i to :be.movedupwardl that the-:mirror'also be moved upwardly to mask-any motionof the exhibitor from behind the reflecting surface; Accordingly, by,the exhibitor himself pulling'slightly at the-bottom of the mirror orreflector, it is possible now to move themirrorupwarldlyby a slightadditional amount and use'theuppersurface of .the'mirror to push againstthe lowermost surface of the hook 38-and to move the hook and itsfastening slider block 65mpwardly-to a position substantially adjacentthe lower side of .thehandrailing II. This then. lifts with-it theropeor tape 40,'but lifts itv tosuch alimited degree as to be unobservable.The additional upward movement of'the reflector 49 and thezhook-tB isusually less than six inches, be-

cause greater amounts are apt to become observable to the lookingaudience.- At these times, then, the person directingthe performance maythrough the utilization of a magical Wave ofthehand to drawathe Iattention of the audienc away from the steps instantaneously indicatethat thethe demonstrators arrange the display programs inzsuch a waythat'the attention of the lookingaudience is normallymomentarily divertedfrom. the apparatus itself at time periods of transition from' one setof operational conditions to another. This wouldgenerally preclude allpossibility that-any observer would be able to sense the shifting ofthemirror or reflector, for'instance, or thechange in'position of themovable step section. relativeto the fixed steps. However, the acev tualprogramming and staging of demonstrations utilizing. the equipmentherein described forms, per se, no part of the invention itself and,therefore, is not herein described in furtherdetail- In the use oftheinvention as an advertising medium it is often particularlydesirablethat the unit be capable of ready dismantling so as to beeasily shipped or moved from placeto place. Ace cordingly, in thepreferred :embodimentof the invention the various componentpartsareiusua ally'so mad and designedwith respect to one anotherthatthe unit asza Whole :may bedisas: sembled and packed in a compact'formoccupying' but relatively little space andtgenerallycoffa length notexceeding that of either the-stepsor the-platform, in a case where-theplatform isnot made in a folded'state-sothat itcanqbe readily, foldedback upon itself Various modifications may be made in-the arrangementsherein disclosed: and therefore these arrangements must 'be'generallyconsidered as diagrammatic. and representative of oneformwhich theinvention may assume.

One of.these modifications might readilybe that-of providing 'only--azsingle fixed step sectiontogether: with the hereinabove-describedmovable section; This would" tendgito' make zthe'complete stair section'of azreduced length; butrinteresting;

effects L: canrnonethelesssbe v5aclilievedrunder such;

terminateinra .flat' or substantially flat platform ortstandingroom-surface abov the movable step section;:. In :this way =the-edgeofthe-flat platform surface woul'dathen form the remaining portion'ofthe normal riser of. the uppermost step.

In another :modification of the invention it is possible. to avoid:the.inclusion of. the, pa eling hereinbeforedescribed; particularly withreferenceto the utilization of thepanel section to guide andsupportthe-edgeof the-mirror. In instances where the panel is omitted it isusually desirable to havea row-of balusters between the hand railingsection andcthe1ends of the steps. One'of the'balusters *atieach end ofthesteps may then be convenientlyarrangedsto mask any motion of themirror'as'it rises and likewis may, of itself,

formthe supportingymediumfor guidingthe edge of the mirror ortreflector.

Also; it will be understood that in some in-- stancess thermovablesection may be arranged in duplicate, triplicate; orin multiple, asdesired. In these instances; of ;course;-the operating mech anism foreach movable'unit may be'generally similar andivariousr-objects orpersons may be-so positioned within the ahousingjthat at times when. thevarious movable sections'have been separated from the fixed sections andthe-reflectors or mirrors located, those objects. or" persons maybecaused'to. appear: as thoughzfloating above or suspended above theremaining-fixed sections. Under these circumstances the plurality offixed sections which will .be'used will portray or simulate the-presenceof each: of the movable sections which have beerrdisplaced-from thecomplete assembly;

The invention'fhas'herein been illustrated also as comprisingsxstepsections: to form a completestaircase. It1'is,ofv course, apparent thatvarious otherxformations maybe substituted for the steps of the sectionso long. 'aswthe arrangement-is of generally symmetrical; shape. Theactual arrangement icy-which: one: couldmove from the lowermost portion?of the-display to the uppermost portion mayiberwhere. desired; in theform of an incline or;ramp,=or it may be in the form of anundulating-surface in which the rises and horizontal extensionsaresubstantially complementary to one another. Accordingly, within the'meaning of the-hereto appended claims it will beunderstood'thatgenerally a staircase section or a stBPZSECtiOIll-iiSitO.be regarded as-termie nology defin-ingzoneror the other of such formsand that referencetto-theillustrated .form of the inventionzwillbe:regarded* as defining generally other sections ofssurfacesusable'forthe purposes described? Havingenow' describedi-the invention, what isclaimed is r s 1. A.-display:.unitz comprising a staircase havingz'afixedly positionedstep section and a movably positioned stepcsectionarranged normallyto bevpositionediin.substantially precise alinementwith the fixeds-section to, form a complete stair section; a-support'forhousing the movable step section, arefiectingz-means supportedrto bemoved b'etweenzthe fixed andmovable step sections. to reflect thefixediseotion and; thereby to provide the:;illusion 10f presence;of-;the; movable section, and. means 2 forsshifitingrathe mo.vab'lestep' section within thehousing-at azrtimewhenxthe reflecting 9 memberis moved to its position intermediate the two sections, said shift ofthe movable section providing an opening behind the reflecting bodythrough which objects may be moved to selected positions relative toeach of the reflecting body and the step sections.

-2. A display unit comprising a staircasehaving at least one fixedlypositionedstair section including a plurality of individual steps and amovably positioned stair section also including a plurality ofindividual steps arranged normally to I be positioned in substantiallyprecise alinement with the fixed stair section, a housing for housingand supporting the movable step section, a reflecting means supported tobe moved intermediate the tread section of the fixed stair sectionjuxtaposed to the riser section of the movable stair section to reflectthe tread sections of the fixed stair section and thereby to provide theillusion of presence of the movable section, and

means for shifting the-movable step section laterally within the housingat a time when the reflecting member is moved to its positionintermediate the two sectionasaid lateral shift of the movable sectionproviding an opening behind the reflecting body through which objectsmay be movedto selected positions relative to each of the reflectingbody and the step sections.

3. A display unit comprising a staircase having a pair of positionedstep sections and a movably positioned step section arranged normally tobe positioned in substantially precise alinement with the'flxed sectionsand intermediate thereof so as normally to form a continuous and usablestaircase, a support beneath the step sections and serving as a housingfor the movable step section, a reflecting means supported to be movedintermediate the fixed and movable step sections to reflect the fixedstep section when viewed from the direction of the fixed section andthereby to provide the illusion of actual presence of the movablesection, and means for shifting the movable step section laterallywithin the housing support at a time when the reflecting member is movedto its position intermediate the two step sections, said lateral shiftof the movable section providing an opening in the housing behind thereflecting body through which objects may be moved to selected positionsrelative to each of the reflecting body and the step sections.

4. A display unit comprising a staircase formed of at least one fixedsection and at least one movable section each in the form of steps andarranged to be brought into precise alinement with one another so as toprovide a usable step section, a support housing of which the fixedstair sectionis arranged to form at least a portion of one outer surfaceand into which the movable and concurrently to-provide an openingintermediate the rear'surface of the reflector and the movable sectionthrough which objects may be moved to selected positions and caused toappear in a location simulating that'of floating above the Stair section'itse1f.-

10 "'5.'.The arrangement claimed in claim4 'com prising, in addition, 'arail section adjacent the end ofe'achof the steps of :each section andextending for substantially the full rise of the combined fixed andmovable step sections, paneling sections between the said rail. and thestep sections, said paneling having angularly extending groovesextending outwardly from substantially the intersection of each riserand tread step section, and at least oneofsaid grooves providing aguiding slot for guiding the reflector in its outward'motion relative tothe step sections.

6; A display unit comprising a staircase formed l of at least one fixedsection and at least one movable section each in the formof steps andarranged to bebrought-into substantially precise registration andalinement with one another so as to provide .a continuous usablestaircase, a

support housing of which the fixed stair section 'is' arranged to format leasta part of one outer surface and into which housing'the movablestair section is adapted to be positioned, a support meansfor carryingthe movable staircase section, a I reflecting element positioned andsupported within the .housing in a plane forming substantiallyequalangles with intersecting adjacent tread and riser sections of the fixedand movable stair sections, respectively, means for moving the reflectorelement to a position such that it reflects the fixed stair section togive the illusion of the actual presence of the movable stair section,and guide and support means sercured withinthe housing for guiding themovable stair section laterally to a position within the housing andconcurrently to provide an opening intermediate the rear surface of thereflector and v the fixed stair section through which objects may bemoved to selected positions and caused to appear in a locationsimulatingthat of protruding above the stair section itself.

7. The arrangement claimed in claim 6 comprising in addition a railsection adjacent the endiofr each of the steps of each of the fixed andmovable sections and extendingfor substantially .the full rise of thecombined step sections, paneling sectionsbetween each of the said railand the step sections, said paneling having grooves extending angularlyoutwardly from substantiallythe intersection of each riser and treadstep sectionto therail to form a guiding slot for positioning and*supporting the reflector in its qoutward motion relative to the stepsections.

8. A display unit comprising a staircase formed of a plurality of fixedstep sections and a movable step section, all of the step sections beingsimilar and arranged to be brought into substantially'precise alinementwith one another so as to provide a continuous and usable staircase, ahousing of which the fixed and movable step sections are normallyarranged to form an outer surface and into which housing the movablestair section may be shiftably positioned to form thereby an opening inthe housing, a reflecting element positioned and supported within thehousing in a plane substantially between adjacent tread and riser.sections of the fixed and movable step sections, respectively, means formoving the reflector element to a position such that it reflects thetreadsof the fixed step section to give the illusion of the actualpresence of the risers of the movable step section, and guide andsupport means secured within the housing for supporting and guiding themovable step section'laterally to a position within the housing andconcurrently to provide an ppening inter- 9. A display unit "comprising:a staircase hav- "ing at least one fixed section and a movable section,:each' of i theisections. comprising. a series of steps whichea'ch'include :treadiand riser sections, and' each ofl'the movable :and'fixed sections being arranged to be brought and fixed substan- I? tiallyinto precise'registration: and alinementiwith one anothen so as"to-providea usable staircase sectiongsaid movable arid fixedsections'ofastepse each havingtreadzand' riser sections of substantiallyequal length andfzthe combined; staircase formed-of the'pluralityofisections-being. arranged to rise: at substantially ian angle of 45?to athorizontal planega housing of which: :the fixed stair section' isarranged to: format least a part of the i outer surface and intowhichnhousing. the .movable stair. section isLadapted to be: positioned,a support COIItaiIIGd 'WithiHLthGl housingz-for carrye-ing andsupportingthetmovable stair section and; =permitting-lateral1 shift -th'ereofinto. the housing to separate the movable'and fixed stair sections,

a reflector .member also supported :within the housing and located. to.slide in-a plane substantiallynormal to the angle of rise of thestaircase and-located at thejunctionrof the tread and rise stairsections of theifixed': and movable. sections respectively, means toshifttthemovable step section laterallyrelative to the fixedly;positioned steps bya distance; substantially equal to that of i thethickness "of the reflecting member, means i to semt-perman'ently:fasten the movable step section in said. positionrfollowing the lateralshift in position; means to move the reflecting member intermediatethet'treadsand risesection of; -the fixed and movablesteps:.-between-.;which it -ispositioned along La plane substantiallynormal to that of the -rise .ofalthe complete staircase, means: toreleasethelmovable step sectionnfrom its semi permanentlysecuredsposition with: the

- positioning f :the 1 reflectir'ig membersv in :its j exten'dedposition,-and meanstoimovebtheimovable stairsection-laterally:upon" its.guide and support -me'ans upon release from the. semi-permanently-secured positi'on so that: therishiftxof themovable v astepsectionsuncovers' anr openingiin the. housing intermediate-therearsurf ace "of: the reflector and the-movablestep section through *whichopening objectsmay be -movedto selected positions relativeto-the fixedly-positioned. steps and the reflector so as-to appear whenvi'ewede'fromMthe front of the reflector and the. fixed. stepsiasfioating in space above the steps.

7 1 0. The arrangement claimed .in :claim: 9 2 comprising in addition ahandrail; section adjacent the end of each of the steps-of eachottherfixed and movable stair sections .and extending a forsubstantially the full'rise of the combinedafixed and movable sectionspaneling 7 sections between each of the" said handrail and the. stepsections,.

said paneling having grooves extending uangularly outwardly fromsubstantially" the intersectioniof each riser and'tread element of-eachstep and in a plane substantially coinciding withthe. plane of motion ofthe reflector, said groove whichintersects the tread and riser membersof .theiflxed 2 tionedi step ":SGCtiOETIandca movable: step.:'sectionlocated thereabover andsrarranged forppositioning J in substantiallyprecise v alinement therewith to of: the formed staircase; panelingmembers intermediate the said rail'asectionsnand theisteps-of thestaircase and having grooved members therein" extending between/the;junction of the :tread hand riser section of -;each.-5 step: of athesta-ircase at and riser members audit-extending; forv substantially the.full distance between: the'said-steps and rail section,--vmeans--formoving the movablerstep section 'to a .semiepermanently locked rpositioninwardly from the:- fixed: step sections aminute ,and' risersections/for providing'the openingbetween; :the 7 lower. Ifixedlypositioned step section t. and the movablestepv section, areflecting:mem-

bar-positioned i-naplane-;to correspond tothe grooves inthe panelingsection, means formovthe complete-"usable staircase, =a: railingvvsection ing the reflecting element in 'the said groove member between.the. fixed: and movable step section and outwardly iromrthe fixedrstepsection toward the railing so lasto-image: the fixed step sectionv andthereby-to simulate-the presence of 1 themovable section, meansoperating to release the movable.step section-.from itssemi-permareflecting member ...through which objects may be moved toselected-positions relativeto the reflecting member. and the fixedmstepsection so as I step section.

to simulatea position :offlfloatingabove the fixed 12. A staircasehaving-apairsof fixedly. positionedstep sections and atmovable stepsection locatedrintermediate the said-two sections in substantiallyprecise A alinement therewith to ..form

eadjacent vthe: ends his eacheofilthe,stepsections and extending forasubstantially the .complete length of. the: staircasepaneling.membersrintermediate=the= said rail sections andit-he-steps -ofthe staircase, said :paneling shaving. grooves itherein extendingbetween the :junction .of. the

45 to 'each ofl the "tread and. .riser rmembersi-for positionedstepwsectionrand-the movable step section, means for: semifi-permanentlyY locating the movable section -in-;1-said last named- -position a spond.tothe grooves in -thegpaneling;section a fastening element 'supported;in thepanelings-sec- I tion groove coinciding withqthatxwhereat the re--.:flecting element is supported;- saidsf-astening elerefiec'ting memberpositicnedsin ai plane-to corrementL-being: .locatedat: a pointgenerally,.=adjacent the railingy-means for movingathe reflectingele--ment :in: thewsaid;;groove.;member1 between .1 the fixed: and movablevstepf-sectionyand: outwardly fromthe fixed. stemsection-r to asubstantially: the

location of the fastening elementinneansppemt- 13 ing to release themovable step section from its semi-permanently secured positioncoincidentally with the positioning of the reflecting membersubstantially adjacent the said fastening member, means operable withrelease of the movable step section for slidably moving the said sectionin a direction inwardly from the two said fixed step sections to providean opening behind the reflecting member through which objects may bemoved to selected positions relative to the reflecting member and thefixed step section so as to simulate a position of floating above thefixed step section, and means for subsequently moving the reflectingmember within the said grooves to a position closer to said railing thanthat of the initial location of said fastening members and concurrentlymoving the fastening 14 members within the grooves to a position closerto the railing section from which position said fastening member isadapted to return to normal position upon the removal of the saidreflecting body from its protracted position.

JOHN P. CAHN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 221,605 Pepper et a1 Nov. 11,1879 914,805 Cross Mar. 9, 1909 1,740,842 Steen Dec. 24, 1929

